Evaluate performance of the Abbott chemiluminescent microparticle immunoassay assay for detection of syphilis infection in Chinese blood donors.

BACKGROUND AND OBJECTIVES: To prevent Treponema Pallidum (TP) transmission from blood transfusion, enzyme-linked immunosorbent assay (EIA) for anti-TP has been widely used in routine blood donation screening in China for many years. The aim of this study was to evaluate the performance of the Abbott CMIA assay for detection of anti-TP in Chinese blood donors. MATERIALS AND METHODS: A total of 2420 plasma samples, already routinely screened for anti-TP by two different EIAs, from four blood Centers were tested for anti-TP by Abbott CMIA. Subsequently, all samples with positive results by one or both EIAs and/or by Abbott CMIA were subjected to confirmatory testing (CT) using recombinant immunoblot assay (RIBA) or Treponema Pallidum particle agglutination assay (TPPA). TP infection was defined by a RIBA or TPPA positive. RESULTS: Compared with two EIAs strategy, Abbott CMIA showed a relatively best sensitivity as 98.80% (95% CI: 97.44%-100.16%) and a relatively best specificity as 99.58% (95% CI: 99.30%-99.85%), yielding the best consistency (99.49%) between anti-TP CT results with the highest κ value of .98. CONCLUSION: This is the first study to evaluate the performance of the Abbott CMIA assays for detection of syphilis in Chinese blood donors. Our results suggested that CMIA performed better than both EIAs, and implementation of CMIA replacing two different EIA reagents might help to further reduce the risk of transfusion-transmitted TP infection, decrease unnecessary blood waste and loss of blood donors.

[The OmpA-like protein Loa22 from Leptospira interrogans serovar lai induces apoptosis in A549 via Ca2+ signal pathway].

OBJECTIVE: To study the effect of Loa22 mature peptide on the apoptosis of A549 to explore the mechanism of pulmonary impairment in severe forms of leptospirosis. METHODS: Loa22 mature peptide (100 microg/mL) was administered to culture with human lung adenocarcinoma cell line (A549). After 24 hours, the apoptosis, the concentration of calcium of the cells were evaluated. The F-actin cytoskeleton structure was observed and calmdulin (CaM) mRNA expression was also detected. At the same time, after the pretreatment of A549 with PLC specific inhibitor U73122, adding an appropriate amount of mature peptide of Loa22 to act on the cells for a period of time, then detection same index. RESULTS: Loa22 mature peptide could induce the increase of intracellular Ca2+ concentration ([Ca2+]i), CaM expression in mRNA level, the activity of LDH, and cytoskeleton rearrangement of F-actin. But after blocking the signal pathway of PLC, Loa22 mature peptide reduced the increase degree of [Ca2+]i, apoptosis rate, the expression of CaM mRNA, the activity of LDH compared with the unblocked group. CONCLUSION: These data suggest that Loa22 mature peptide involves in the pathological processes of L. interrogans invasion and increase apoptosis in A549 by increase of [Ca2+]i through signaling pathway of PLC.